Wood generally refers to the wooden materials used in industrial and civil construction, and is usually divided into soft wood and hard wood. The timber used in the works is mainly taken from the trunk of the trees. Wood has been a staple building material since ancient times because it is easy to obtain and process.
Timber is classified according to tree species, which are generally divided into coniferous and broad-leaved wood.
Preservative wood is a wood that uses preservatives to penetrate and solidify the wood, so that the wood has the function of preventing decay from decaying bacteria and biological damage.
Timber can be divided into two main categories: coniferous and broadwood. Fir and various types of pine, spruce and fir are coniferous trees, while oak, ash, camphor, sassafras and various types of birch, nanmu and poplar are broad-leaved trees. There are many tree species in China, so the timber species commonly used for engineering in different regions are also different. In Northeast China, there are mainly Korean pine, larch (Huanghua pine), fish scale spruce, red spruce and ash, the Yangtze River basin mainly has Chinese fir and Masson pine, and the southwest and northwest regions mainly have fir, spruce and hemlock.
